:root {
  --primary: #0d1b2a;
  --secondary: #1b263b;
  --accent: #00c6ff;
  --highlight: #39ff14;
  --text: #ffffff;
  --text-secondary: #d3d3d3;
  --radius: 8px;
  --shadow: 0 4px 20px rgba(0, 198, 255, 0.2);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

@font-face {
  font-family: 'Montserrat';
  src: url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;600;700&display=swap');
}

body {
  background: radial-gradient(circle at 10% 20%, #0d1b2a 0%, #050a12 100%);
  color: var(--text);
  font-family: 'Montserrat', sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.header {
  position: relative;
  padding: 40px 0;
  text-align: center;
  background: linear-gradient(135deg, rgba(13,27,42,0.8) 0%, rgba(27,38,59,0.9) 100%);
  border-bottom: 1px solid rgba(0, 198, 255, 0.3);
  margin-bottom: 60px;
  overflow: hidden;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample3.png') center/cover no-repeat;
  opacity: 0.1;
  z-index: -1;
}

.header h1 {
  font-size: 2.8rem;
  margin: 0;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 0 20px rgba(0, 198, 255, 0.3);
  letter-spacing: 1px;
}

.header p {
  color: var(--text-secondary);
  max-width: 800px;
  margin: 20px auto 0;
  font-size: 1.2rem;
}

.note {
  background: rgba(0, 198, 255, 0.1);
  border-left: 4px solid var(--accent);
  padding: 15px;
  margin: 30px 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.9rem;
}

.note::before {
  content: "这是一个网页样式设计参考";
  display: block;
  font-weight: bold;
  margin-bottom: 8px;
  color: var(--accent);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 30px;
  margin: 50px 0;
}

.card {
  background: linear-gradient(145deg, var(--secondary), #12263a);
  border-radius: var(--radius);
  padding: 30px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 198, 255, 0.3);
}

.card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
}

.card h2, .card h3 {
  color: var(--accent);
  margin-top: 0;
  position: relative;
  display: inline-block;
}

.card h2::after, .card h3::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 50px;
  height: 2px;
  background: var(--highlight);
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 15px;
  margin: 20px 0;
}

.image-grid img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
  transition: var(--transition);
  opacity: 0.8;
}

.image-grid img:hover {
  transform: scale(1.05);
  opacity: 1;
  box-shadow: 0 8px 20px rgba(0, 198, 255, 0.4);
}

pre {
  background: #12263a;
  border-radius: var(--radius);
  padding: 20px;
  overflow-x: auto;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
  border-left: 4px solid var(--accent);
  margin: 20px 0;
}

code {
  font-family: 'Courier New', monospace;
  color: var(--highlight);
}

.nav-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 15px;
  margin: 40px 0;
}

.nav-link {
  color: var(--text);
  text-decoration: none;
  padding: 10px 20px;
  border-radius: 30px;
  background: rgba(0, 198, 255, 0.1);
  border: 1px solid rgba(0, 198, 255, 0.3);
  transition: var(--transition);
  font-weight: 600;
  position: relative;
  overflow: hidden;
}

.nav-link::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 198, 255, 0.2), transparent);
  transition: all 0.6s ease;
}

.nav-link:hover {
  background: rgba(0, 198, 255, 0.2);
  transform: translateY(-2px);
}

.nav-link:hover::before {
  left: 100%;
}

.footer {
  text-align: center;
  padding: 30px 0;
  margin-top: 60px;
  border-top: 1px solid rgba(0, 198, 255, 0.3);
  color: var(--text-secondary);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.floating {
  animation: float 3s ease-in-out infinite;
}